I. Field of the Invention
The present invention relates to a rotary type sampling apparatus for powdered or granular materials.
The first variant of the present invention relates to a sampling apparatus wherein a rod-like body having a rotary measuring table is designed to be inserted into a bed of powdered or granular materials in a storage container such as a hopper dryer through an external wall of the storage container for powdered or granular materials and a sample of the powdered or granular materials are forcedly pneumatically discharged and automatically taken out by rotating the measuring table and feeding a pressurized gas.
The second variant of the present invention relates to a rotary sampling apparatus which is designed to be incorporated into a mounting pedestal provided for a material storage container and a sample of the powdered or granular materials are forcedly pneumatically discharged and automatically taken out by rotating the measuring table and feeding a pressurized gas.
II. Prior Art
Generally, taking an example of resin materials as powdered or granular materials, it is very important to maintain an appropriate moisture content of the resin materials in view of maintaining good quality of the resin materials because products molded from the resin materials have damages such as a silver line or voids when the moisture content of the resin materials is inappropriate. Therefore, resin materials have always been dried in a hopper dryer for a fixed time before the materials are fed into a moulding machine.
However, it has been difficult to maintain the moisture content of the resin materials constant even if the materials have been dried for a fixed time because the moisture content of resin materials differs depending on the season or other conditions. Therefore, it has proven troublesome to measure the moisture content of resin materials by monitoring drying conditions such as a heating temperature of the hopper dryer which is minutely controlled depending on the measured moisture content.
Manufacturers of resin materials control the quality of the resin materials by repeatedly checking the moisture content thereof when the materials are shipped. However, the checking is all done manually by operator's and this takes a lot of time and labor. Therefore, automation of such checking is desirable but has been considered very difficult.
However, it is necessary to sample resin materials continuously fed at regular intervals for measuring the moisture content of the materials. So, labor saving and automation of such a sampling operation are desired. However, at present, people other than resin manufacturers perform checking of the moisture content of the materials with only a few samplings and only a few times.
Further, the moisture content of resin materials has been generally calculated from the moisture weight contained in the sampled resin materials. In such a case, the weight of the sampled resin materials must not differ in order to calculate an accurate moisture content. Therefore, a high precise quantitative sampling has been desired.